ES2634916T3 - A panel comprising a layer of polymer composite and a reinforcing layer - Google Patents

Abstract

A panel (1), comprising a layer of polymer composite (2) and at least one reinforcement layer (3) to reinforce the layer of polymer composite (2) at least in the plane of the panel (1), where The reinforcement layer (3) is incorporated into the layer of polymer composite (2) and is made of a material that is different from that of the layer of polymer composite (2), where the reinforcement layer is more thin than the layer of polymer composite.

Description

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DESCRIPTION

A panel comprising a layer of polymer composite and a reinforcing layer

The present invention relates to a panel, in particular a floor panel comprising a layer of polymer composite.

From WO 2008/122668, a panel having a layer of a polymeric compound is known. In this case, the polymeric compound is WPC, which is a composite material of polymeric material and a natural fiber, for example, from any source of wood. Due to the presence of polymers, the dimensions of the known panels depend more strongly on the temperature than, for example, wooden boards or panels made mainly of wood-based material, which limits the applicability of panels that include a layer of WPC.

An object of the present invention is to provide a panel that includes a layer of polymeric composite material that is applicable under changing environmental conditions.

For this purpose, the panel according to the invention comprises the features of claim 1. The reinforcing layer can also reinforce the polymer composite layer in a direction that extends transversely to the plane of the panel.

An advantage of the panel according to the invention is that the deformation of the polymer composite layer in the panel plane is minimized. In other words, the sensitivity of panel dimensions to environmental conditions is minimized. This means that the panel can be applied in places where environmental conditions change, for example in the case of floor panels that are connected to each other to form a floor covering on a floor that has a floor heating system. Furthermore, in the case of floor panels that are mutually connected to form a floor covering, the expansion space between the wall and an adjacent floor panel can be minimized. The reinforcing layer is thinner than the polymer composite layer, for example less than 0.4 mm, but a thicker thickness is possible. It is noted that the reinforcing layer may be a sheet or plate; The layer can be self-supporting and / or can be made in one piece.

The polymeric composite material may be a mixture of one or more polymers and non-polymeric or partially polymeric material. Examples of non-polymeric or partially polymeric materials are waste of carpets and limestone, jute, styrene butadiene (latex), but many alternative materials are conceivable. The polymeric composite material may also contain a coupling agent to improve the cohesion of the material. Alternative additives are elastomers or materials that have a high absorption capacity of fillers. This can also improve features such as UV resistance, moisture resistance and flexural strength. The fillers can be fibers, powders or the like. In general, the layer of polymeric composite material can be a compound of a polymer and a non-polymeric composite substance. The composite substance may be natural, unnatural, particulate or similar fibers. In a practical embodiment the polymer composite layer is a WPC layer made of plastic and wood composite material (WPC) and the reinforcement layer is a reinforcement layer other than WPC.

The reinforcing layer is incorporated into the polymer composite layer since this creates an effective reinforcement of the polymer composite layer. As for the manufacture of such an embodiment, the reinforcing layer can easily be integrated into a known pressing process for manufacturing a polymer composite panel such that the reinforcing layer is embedded within the polymer composite layer. Such a procedure is described in WO 2008/122668.

The reinforcing layer may have an open structure. The advantage is that by pressing the layers of molten granulate together while the reinforcement layer is sandwiched between the layers, a strong bond between the layers of molten granulate can be achieved in open areas of the open structure. As a result, the reinforcing layer is fully integrated in the polymer composite layer without significantly weakening the panel in the reinforcing layer in a direction perpendicular to the plane of the panel. Thus, the resulting polymer composite layer is continuous through open areas of the open structure, that is, in a direction perpendicular to the plane of the panel.

The reinforcing layer may comprise longitudinal filaments and transverse filaments that extend in a transverse direction with respect to the longitudinal filaments. The filaments may be oriented perpendicularly to each other, but this is not necessary. The mutual distance of at least one of the longitudinal filaments and transverse filaments may vary within the reinforcement layer, which provides the opportunity to create stronger reinforcement in predefined areas of the panel. For example, the mutual distance can vary between 1-5 filaments per cm. It is advantageous when the mutual distance is adapted to the size of the granulate from which the polymer composite layer is made; in particular if the granulate is not completely molten, it can still pass through the reinforcement layer when pressed. The filaments can be made of fiberglass, or high tenacity polyester fibers, polyester textile, cellulose, aramid, PEN, Nomex or other materials that are dimensionally insensitive to changing environmental conditions such as temperature changes.

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It is noted that the filaments can be fixed together by means of fixing, for example glue. The filaments and fixing means will be selected so that they are compatible with the polymeric compound and preferably form a strong bond therewith. In addition, binders can be added to the polymer composite and / or the reinforcing layers, such as ethylene vinyl acrylate, polyurethane, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, styrene-butadiene or the like.

The panel may comprise at least one other reinforcement layer, which is preferably located at a distance from the reinforcement layer. A plurality of reinforcement layer is also possible. The reinforcing layers may be located within the polymer composite layer,

The panel according to the invention can be a floor panel, a ceiling panel, a wall panel or the like.

The invention will be explained below with reference to very schematic drawings showing an embodiment of the invention by way of example.

Fig. 1 is an enlarged sectional view of an embodiment of a panel according to the invention.

Fig. 2 is a series of very schematic top views of different types of reinforcing layers that are applicable in the panel according to Fig. 1.

Fig. 3 is a series of perspective views of different types of reinforcing layers that are applicable in the panel according to Fig. 1.

Fig. 4 is a very schematic view of an apparatus for manufacturing a panel of Fig. 1.

Fig. 1 shows a cross-sectional view of an embodiment of a floor panel 1 according to the invention. The floor panel 1 includes a WPC 2 layer made of plastic and wood compound granules (WPC) and a reinforcement layer 3. The reinforcement layer 3 is thinner than the WPC 2 layer and is intended to minimize the dimensional changes of the WPC 2 layer in the panel 1 plane. In this mode the reinforcing layer 3 is incorporated into the WPC 2 layer so that the portions of the WPC 2 layer extend to both sides of the reinforcing layer 3, for stability reasons it is preferred that the thicknesses of these portions of the WPC 2 layer be substantially equal. It is noted that instead of WPC an alternative polymeric compound can be applied.

In addition, the floor panel 1 according to Fig. 1 includes an upper laminate on the WPC layer 2. In this example, the upper laminate is a high pressure laminated construction comprising less a printed decorative layer 4 and an overlay protective impregnated 5 pressed together with heat and pressure to become a single layer due to the impregnating material which is preferably a resin such as melamine resin. Preferably, the melamine resin is mixed with urea-formaldehyde to obtain advantageous properties such as shrinkage minimization and turbidity reduction. The overlay paper 5 is preferably a high abrasive overlay that preferably has aluminum oxide or other hard abrasion resistant particles embedded in the paper surface. It is noted that a different type of layer can be provided on the WPC layer, for example a polymeric film having a decoration pattern, which is printed on the film. The polymeric film may melt to the layer.

The top laminate or top layer as described above consists of one or more layers of paper, but one or more layers of wood cladding, vulcanized cellulose layers or other suitable layers can also be conceived as top layer.

The design and the general upper layers can be textured as embossed in the register with the design of the printed decorative layer in order to imitate even better the natural material, such as stone, brick, ceramic, wood, marble or the like.

Preferably, but not necessarily, a support layer 6 is provided below the WPC layer 2 and is fixed to the bottom side of the WPC layer 2. The support layer 6 can be used as a stabilizing layer and can also have properties of moisture resistance In addition, a paper layer 7 can be provided between the WPC layer and the top laminate.

At least on two opposite sides of the floor panel 1 and preferably on all sides coupling means 8 are formed to couple the adjacent panels 1. Preferably, the coupling means 8 also includes a mechanical locking system for locking the floor panels adjacent 1 not only in a direction perpendicular to the surface of the panels, but also in a direction parallel to the surface and perpendicular to the respective side of the floor panel 1. However, the invention is not limited to them at all. Although Fig. 1 shows a tongue and a groove as a coupling means 8, all coupling systems, including the use of adhesives, are comprised by the invention.

In a preferred embodiment, the reinforcement layer 3 has an open structure, since this allows the portions of the WPC layer 2 on both sides of the reinforcement layer 3 to be contacted during manufacturing, creating

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therefore an integral structure of the WPC layer 2 and the reinforcement layer 3. Fig. 2 shows several examples of reinforcement layers 3 that include an open structure. The reinforcing layers 3 as shown comprise parallel longitudinal filaments 9 and parallel transverse filaments 10 which extend in a transverse direction with respect to the longitudinal filaments 9. The filaments 9, 10 are oriented such that they surround open areas 11. Although the Longitudinal filaments 9 and transverse filaments 10 in the embodiments are oriented perpendicularly with respect to each other, this is not necessary. Fig. 2 also shows that the reinforcement layers 3 can vary with respect to the mutual distances of the filaments 9, 10 in different directions, even within the specific portions of the reinforcement layer 3, and in the dimensions of the filament.

Fig. 3 shows examples of different reinforcement layers 3 in perspective view. The longitudinal filaments 9 and transverse filaments 10 can be placed one above the other and can be mutually joined at intersections of the filaments 9, 10. Alternatively, the longitudinal filaments each comprise parallel filaments 9 ', 9 "which are joined together along of the filaments 9 ', 9 "and interrupted by the transverse filaments 10 that are sandwiched between the parallel filaments 9', 9 '' at the intersections of the filaments 9 ', 9" and the transverse filaments 10. Also, the filaments 9 , 10 can be laminated generating a fabric 11, for example a non-woven material, as illustrated in the bottom drawing of Fig. 3.

Fig. 4 shows an apparatus 12 for manufacturing laminated sheets S that may include a plurality of panels 1 (see Figure 1) that are cut from the sheets S and terminated in a manner well known in the prior art.

The apparatus 12 includes a first supply of granulate 13 that includes a mechanism 14 that is adapted to supply a first layer of granulate 15 on a support conveyor belt 16. The apparatus 12 also includes a second supply of granulate 17 that includes a mechanism 18 which is adapted to supply a second layer of granulate 19.

Between the first granulate supply 13 and the second granulate supply 17, the reinforcement layer 3 is supplied by unrolling it from a supply roller. The second granulate layer 19 is supplied on the reinforcement layer 3.

The granulate is made of wood / plastic composite material that is a material known in the prior art. It can include from about 30% by weight to about 95% by weight of at least one polymeric material and from about 5% by weight to about 80% by weight of at least one fiber or natural flour by weight of the WPC layer. Alternatively, the polymeric composite material includes fibers, particles, flour or the like, comprising one or more polymers per se, to which one or more polymeric materials are possibly added. The polymeric material may be one or more polymers having a polyolefin group, such as polyethylene. Other exemplary polymers include polypropylene, polyvinyl chloride, PVC copolymer and other suitable thermoplastic materials. The polymeric material that must be processed may be in powder, liquid, in cubes, in the form of pellets and / or in any other form. The polymeric material can be virgin, recycled or a mixture of both. Additionally, the polymeric material can be provided with natural or unnatural additives, and / or a coupling agent to improve the cohesion of material. The polymeric material can be incorporated with a blowing agent to form a core of cellular foam structure.

Natural fibers or flour have a specific moisture content, depending on the WPC board specifications and requirements. Natural fibers can be from any wood source, cellulose source, other natural sources, or any combination thereof. Generally, any natural fiber can be used, which is from trees, plants, parts thereof and the like. The specific selection of a particular type of wood and / or wood fibers may have an influence on the properties of the final panel. The fibers of an exotic hardwood type could be, for example, substantially thicker and / or longer than normal spruce wood. The flexural stiffness will be greater if the WPC layer is made with longer fibers. Synthetic fibers can also be used to improve mechanical properties such as flexural and tensile moduli of the product. Natural fiber or flour can be virgin, recycled or a mixture of both. In addition, natural fibers or flour can be incorporated with a foaming agent to manufacture a core of cellular foam structure.

The mechanisms 14, 18 may include a system provided by Schilling-Knobel GmbH, as described in WO 99/26773, which is incorporated herein by reference thereto, including a hopper resting on a measuring roller that collects the material to be dispersed on the conveyor belt 16, other means are, of course, conceivable.

The lower conveyor belt 16 has a length greater than a second upper conveyor belt 20 which is located at a distance from the first and second granulate supply 13, 17.

The upper and lower conveyor belt 16, 20 extend over a certain length parallel to each other and include several zones. The first zone in the transport direction of the conveyor belts 16, 20 is a heating zone 21. In this zone, the WPC granulate is heated to such a temperature that the granulate melts sufficiently to weaken to a mass that is molded. in a solid continuous sheet. The temperature of

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heating depends on the polymer used in the WPC granulate and can be for example between 180 ° C and 2502C. In this exemplary embodiment, the heating zone 21 is divided into a first heating zone 21A and a second heating zone 21B with pressure rollers 22 between them. These pressure rollers 22 are located below the transport part of the lower conveyor belt 16 and above the transport part of the upper conveyor 20 to effect a first pressure action on the layers 15, 19 of the molten granulate. A second set of pressure rollers 23 consisting of two pairs of lower and upper pressure rollers performs a final pressing action on the layers 15, 19 of the molten granulate and determines the final thickness of the sheet to be formed.

As described above, the reinforcing layer 3 preferably has an open structure such that the first and second layers of the molten granulate 15, 19 are pressed together through the open areas 11 of the reinforcing layer 3. This avoid any weak bond between layers 15, 19 due to the addition of reinforcement layer 3.

The last area within the conveyor belts 16, 20 is an annealing zone 24 whereby the layers of sheet 15, 19 are cooled and brought to the final shape. The conveyor belts 16, 20 are formed by two thermally stable and reinforced coated belts, for example of glass plus Teflon®. The rear sides of the belts are in contact with the heating plates in the heating zones 21A, 21B and with the cooling plates in the annealing zone 24. The plates in the upper conveyor belt 20 are movable in the vertical direction, while that the plates on the lower conveyor belt 16 are rigidly mounted. The mobility of the plates with the upper conveyor 20 is to create a separation according to the required thickness of the sheet to be formed. In principle, the heating and cooling plates do not exert pressure on the granulate layers 15, 19 and only the pressure rollers of calibration 22, 23 are adapted to exert pressure on the molten granulate layers 15, 19 to determine their thickness.

As illustrated in Fig. 4, a layer of paper or other absorbent material 6, 7 is supplied to the lower side of the first layer 15 and upper side of the second layer 19 of granulate 3 so that it melts thereto, i.e. , so that they join them through the molten plastic of the granulate. Paper layers 6, 7 are supplied by unrolling them from the supply rollers. The paper layers 6, 7 are interposed between the first granulate layer 15 and the lower conveyor belt 16 and between the second granulate layer 19 and the upper conveyor belt 20, respectively, so that they also help prevent the layers of granules 15, 19 stick to the conveyor belts 16, 20. The transport speed of the paper layers 6, 7 and the reinforcement layer 3 will be adapted to that of the conveyor belts 16, 20, so that they fit, but it is also possible that they are not positively supplied, but that they are dragged by the friction between the paper and the reinforcing layers and the granulate layers 15, 19 and the conveyor belts 16, 20.

Instead of the paper layer 7, it is possible to supply a polymeric sheet, for example PVC polypropylene, polyester or the like, to the molten granulate layer of the WPC layer. The polymeric film melts and as a result after pressing, the resulting panel obtains a smooth surface on the side where the polymeric sheet is provided and melts. This is advantageous if the WPC layer has a thick surface due to the non-homogeneous mixing of the polymer and a composite substance. In addition, the molten polymeric layer on the WPC layer can also improve the stability and stiffness of the resulting panel and further improve the adhesion of yet another polymeric film thereon provided at a later stage such that it does not melt completely. This additional polymeric film may be provided with a decoration pattern. It is also possible to provide a molten polymeric layer or film on the back side of the WPC layer, which can function as a stabilizing layer.

In a downstream position of the upper conveyor belt 20 a cutting mechanism 25 is arranged to cut the continuous sheet coil into separate sheets S which are then collected for further processing to form the floor panel 1 as shown in Fig. . one.

An alternative method of manufacturing the panels according to the invention is one in which an upper laminate and optionally also a support layer is fixed directly to the WPC layer simultaneously with the formation of the WPC layer including the reinforcement layer 3. This means that the (paper) layers 6 and 7 are then formed by the materials to form the upper laminate and the support layer that are fixed directly to the WPC layers by adhesion thereto. The upper laminate must then be of such a structure that it can be supplied in rollers and can be fixed directly to the second layer of WPC. The top laminate or top layer may consist of layers of paper, but one or more layers of wood cladding or layers of vulcanized cellulose may also be conceived in accordance with the present invention, as long as they withstand heat during pressing. In another alternative embodiment, the upper laminate can be left out and the decoration can be printed directly on the WPC material. Alternatively or additionally, the raw WPC material can be etched and / or ground / sanded in a particle pattern to mimic natural materials such as wood or stone.

From the above, it will be clear that the invention provides a panel whose dimensions are stable despite variable environmental conditions.

Claims (15)

5 10 fifteen twenty 25 30 35 1. A panel (1), comprising a layer of polymeric composite material (2) and at least one reinforcing layer (3) to reinforce the layer of polymeric composite material (2) at least in the plane of the panel (1) , where the reinforcement layer (3) is incorporated into the polymer composite layer (2) and is made of a material that is different from that of the polymer composite layer (2), where the reinforcement layer It is thinner than the polymer composite layer. 2. A panel (1) according to claim 1, wherein the polymer composite layer (2) is a WPC layer (2) made of the plastic and wood composite material (WPC) and the reinforcing layer ( 3) is a reinforcement layer other than WPC (3). 3. A panel (1) according to claim 1, wherein the polymeric composite material is a mixture of one or more polymers and non-polymeric material, wherein the non-polymeric material is limestone. 4. A panel (1) according to one of the preceding claims, wherein the reinforcing layer (3) has an open structure. 5. A panel (1) according to claim 4, wherein the polymer composite layer (2) is continuous through open areas (11) of the open structure. A panel (1) according to one of the preceding claims, wherein the reinforcing layer (3) comprises a fiber coil. A panel (1) according to one of the preceding claims, wherein the reinforcing layer (3) comprises longitudinal filaments (9, 9 ', 9 ") and transverse filaments (10) extending in transverse direction with respect to to the longitudinal filaments (9, 9 ', 9' '). A panel (1) according to claim 7, wherein the mutual distance between the longitudinal filaments (9, 9 ', 9 ") and / or the transverse filaments (10) varies within the reinforcing layer. 9. A panel (1) according to claim 7 or 8, wherein said filaments are made of fiberglass, and are fixed to each other by fixing means and where binders are added to the reinforcing layer. 10. A panel (1) according to one of the preceding claims, wherein the reinforcing layer is a sheet or plate. 11. A panel (1) according to one of the preceding claims, wherein the reinforcing layer is made in one piece. 12. A panel (1) according to one of the preceding claims, wherein the panel (1) comprises at least one other reinforcement layer, preferably located at a distance from the reinforcement layer (3). 13. A panel (1) according to one of the preceding claims, wherein the polymer composite layer contains at least 30% polymer. 14. A panel (1) according to one of the preceding claims, wherein the panel is a floor panel and at least on two opposite sides of said floor panel, coupling means are formed to couple adjacent floor panels . 15. A panel (1) according to one of the preceding claims, wherein a polymeric film is provided on the layer of polymeric composite material, wherein said polymeric film has a decoration pattern that is printed on the film.